The effect of body mass index on short-term outcomes in nonagenarians and centenarians with critical illness: A retrospective cohort study
Issued Date
2026-04-01
Resource Type
eISSN
23525568
Scopus ID
2-s2.0-105019754486
Pubmed ID
41033448
Journal Title
Anaesthesia Critical Care and Pain Medicine
Volume
45
Issue
2
Rights Holder(s)
SCOPUS
Bibliographic Citation
Anaesthesia Critical Care and Pain Medicine Vol.45 No.2 (2026)
Suggested Citation
Hinton J.V., Raykateeraroj N., Ker C.J., Waldman B., Suh J.M., Pilcher D., Bellomo R., Lee D.K., Weinberg L. The effect of body mass index on short-term outcomes in nonagenarians and centenarians with critical illness: A retrospective cohort study. Anaesthesia Critical Care and Pain Medicine Vol.45 No.2 (2026). doi:10.1016/j.accpm.2025.101634 Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/114354
Title
The effect of body mass index on short-term outcomes in nonagenarians and centenarians with critical illness: A retrospective cohort study
Corresponding Author(s)
Other Contributor(s)
Abstract
Background: The impact of body mass index (BMI) on morbidity and mortality in very old individuals with acute, critical illness is poorly understood. Methods: We conducted a bi-national, retrospective, entropy-weighted cohort study of 12,510 nonagenarians and centenarians admitted to the intensive care unit (ICU) over a 15-year period. Based on their admission BMI, patients were classified as underweight (BMI < 20 kg/m<sup>2</sup>), normal weight (20 kg/m<sup>2</sup> ≤ BMI < 25.0 kg/m<sup>2</sup>), overweight (25.0 kg/m<sup>2</sup> ≤ BMI < 30 kg/m<sup>2</sup>), or obese (BMI ≥ 30 kg/m<sup>2</sup>). We estimated the association between admission BMI and clinical outcomes, with in-hospital mortality as the primary outcome. Results: The median BMI of the cohort was 24.4 kg/m<sup>2</sup>(IQR 21.8–27.5). Of the 12,510 eligible patients, 5,471 (43.7%) were categorized as normal weight, 1,526 (12.2%) underweight, 3,914 (31.3%) overweight, and 1,599 (12.8%) obese. After entropy weighting, increasing BMI was negatively associated with mortality (P < 0.001). In-hospital mortality occurred in 699 (12.8%) normal weight, 223 (14.6%) underweight (relative risk [RR] 1.18; 95% CI 1.02–1.36; P = 0.030), 504 (12.9%) overweight (RR 0.97; 95% CI 0.87–1.08; P = 0.580), and 172 (10.8%) obese (RR 0.76; 95% CI 0.64–0.90; P = 0.001) patients. BMI was not associated with binary requirements for inotropes, invasive ventilation, or renal replacement therapy. Conclusions: In nonagenarians and centenarians admitted to the ICU, higher BMI was linked to lower in-hospital mortality, suggesting a protective effect. These results emphasize the need for individualized risk assessment in older ICU patients. Australian New Zealand Clinical Trials Registry number: ACTRN12625000297426.